The primary test for heart hormones involves measuring natriuretic peptides in the blood. Specifically, the tests commonly used are the BNP (B-type natriuretic peptide) test and the NT-proBNP (N-terminal pro-B-type natriuretic peptide) test.
Natriuretic Peptide Tests: BNP and NT-proBNP
Natriuretic peptides are hormones produced by the heart and blood vessels. They help regulate blood pressure and fluid balance. When the heart is strained, such as in heart failure, the body produces more of these peptides. Measuring the levels of BNP or NT-proBNP in the blood can help doctors:
- Diagnose Heart Failure: Elevated levels can indicate heart failure, especially in patients experiencing symptoms like shortness of breath or swelling in the legs.
- Assess the Severity of Heart Failure: Higher levels generally correlate with more severe heart failure.
- Monitor Treatment: Tracking BNP or NT-proBNP levels over time can help assess how well heart failure treatment is working.
- Rule Out Heart Failure: If BNP or NT-proBNP levels are normal, heart failure is less likely.
How the Tests are Performed
Both BNP and NT-proBNP tests are simple blood tests. A healthcare professional will draw a blood sample from a vein in your arm and send it to a laboratory for analysis.
Interpreting the Results
The interpretation of BNP and NT-proBNP levels depends on the specific assay used by the lab, as well as the patient's age, sex, and other medical conditions. Generally:
- Normal Levels: Low levels of BNP or NT-proBNP usually indicate that heart failure is unlikely. However, other heart conditions could be present.
- Elevated Levels: Higher levels suggest heart failure, but further evaluation is needed to confirm the diagnosis and determine the cause.
It is important to note that elevated BNP or NT-proBNP levels can also be caused by other conditions, such as kidney disease, lung disease, and advanced age. Therefore, the results of these tests should always be interpreted in the context of a complete medical evaluation.
